With improvements in toothbrush technology, power toothbrushes such as acoustic or sonic toothbrushes that vibrate at sonic frequencies, approximately 200 to 500 Hz, have been developed and are now widely used. A typical power toothbrush includes a toothbrush body that functions as a handle and a toothbrush head that is removably coupled to the toothbrush body. The toothbrush head includes a plurality of bristles affixed thereto. The toothbrush body includes a toothbrush driver that is adapted to vibrate the toothbrush head and, thus, the bristles affixed thereto. When the bristles on the toothbrush head vibrate against a user's teeth, the vibrating bristles both scrub contaminants off the tooth enamel and massage the adjacent soft gum tissue.
After some use, however, the toothbrush bristles tend to be broken down, split, or otherwise become ineffective for cleaning teeth or massaging gum tissue. Also, during prolonged use of a sonic toothbrush, its bristles may become unsanitary through accumulation of biodegradable debris and bacteria, especially around and in the bristles' sockets.
Thus, a need exists for a use indicator suitable for use with a power toothbrush, which is adapted to notify a user when to replace a toothbrush head before it loses its effective brushing ability or becomes unsanitary. Preferably, such a use indicator should be able to produce an easily detectable indication to a user after a predetermined period of time or period of use of the toothbrush. Such indicator would also find use with other devices where use of the device could be related to vibration of the device.